Bukh DV36 life

[jtwebb]

I am going to look at a LM32 with a Bukh DV36 engine with fresh water cooling when we are free to travel again. My concern is the life of the engine as it has done 4000 hours. One way I am looking at it is that is equivalent to up to 200000 miles in a van! I did have a 2 cyl Bukh in a Westerly Fulmar and did have an exhaust elbow failure after I had checked it that winter by hammer tapping to check it sounded OK. Also does the 3 cyl fresh water cooled engine have the same water pump seal problem?

 

[Boater Sam]

4k hours is not a lot if maintenance has been good.
I would be more concerned about internal corrosion especially if it has been on salt water. Checking the waterway anode would give you some clue, if there is nothing left then I would check further.
The pumps are AFAIK the same.

 

[jtwebb]

Can't remember where that anode screws in. I was very careful about replacing it on my Fulmar. It does have fresh water cooling with the heat exchanger which I guess can gunge up.

 

[lornagrace]

if it's feshwater cooling as stated then there shouldn't be any worries..
Buhk are dedicated marine engines normally found in life boats etc and are pretty bulletproof.

 

[jtwebb]

Thanks and I am indeed happier at the point that it is freshwater cooled. I knew it goes into many ship lifeboats, just didn't reckon they did many hours!

 

[Boater Sam]

Fresh water only through the heat exchanger and exhaust elbow? So the block is a sealed system and should be OK if it has had good antifreeze in it all the time?
Anode I think is on the back of the block just beloew the head gasket.

 

[jtwebb]

Won't be fresh in the exhaust elbow as the salt water must exit via that thing. I reckon it should be replaced at £480 or so!

 

[Boater Sam]

Er, that's what I said, Fresh = salt if at sea otherwise its just fresh. The elbow obviously is not dumping the antifreeze!

 

[jtwebb]

Read it too quickly, sorry.

 

[Boater Sam]

Easy to do, happens to me all the time, if I can read it at all, myopia.

 

[jwilson]

4000 hours is nothing for a FW cooled marine diesel engine as long as it has had reasonable maintenance. Yes, things like exhaust elbows may need replacing, but that is no different to changing tyres or brake pads on a car: it's something needed every so often. My engine has done just under 5,000 hours, starts instantly from cold, makes no smoke, burns very little oil, but has had three new exhaust elbows and I think three starter motors in it's life.

I'd compare 4,000 hours with 120,000 in a van or car, and on an engine that revs less and produces less bhp per litre capacity. Plenty of vans clock up 250,000 on their diesels, and 8,000 hours is often suggested as a life of a small marine diesel, though plenty of small commercial fishing boats get a lot more than that out of them.

 

[jtwebb]

Thanks for all that, I have a vague memory that the Hayling Southsea ferry engine was only stopped at Christmas and Easter! I don't know when the fresh water system was added, something to be found out. The system works with an electric pump to circulate the fresh water. I have experience of that elbow on a Fulmar. It was a pig when it failed in Lezardrieux but the people in Poole got me a new one quickly. I had, I thought, carefully checked it the previous winter.

 

[Boater Sam]

. The system works with an electric pump to circulate the fresh water.


Novel, I'd definitely have a spare pump aboard!

 

[seaangler23]

I have a raw water cooled 48 with about 2500 hours on it, really is a great engine very quiet and smooth and economical but the downside of them is they are made by bukh not an adaption of a commonly found engine such as Kabota, so 90% of spares have to come from them and they are not cheap and they can be a pain to get the bits.
Took about a month to get a turbo manifold from them even though I had the part number of the manifold, turbo, engine and had to send pics with measurements and in the end just had to hope what they sent was right as they didn’t know.
Mine will go through 2 anodes in a season, 24mm brass bolt on the water manIdold below the inlet.
Mine runs an electric pump for the calorifier circuit, I’d be wary of one running the engine circuit, at the very minimum run an exhaust temperature alarm and keep a spare.

 

[jtwebb]

Very good point about exhaust temperature alarm and spare pump thanks. I did have a 2 cylinder Bukh in a Fulmar 20 odd years ago and did have an exhaust elbow fail when leaving Lezardrieux. Bit peeved because I did inspect and hammer tap for signs of cracking in the winter. I used to check that anode annually, wonder about fresh water cooling and the effect on the anode life.

 

[doug748]

Won't be fresh in the exhaust elbow as the salt water must exit via that thing. I reckon it should be replaced at £480 or so!

I thought the Beta one was a bit steep at c£220 and did consider having one made up - that could be an option. Or maybe having the old one welded up / refurbished locally, as a spare and fitting a new one for peace of mind.

 

[jonic]

Did 8000 hrs in my last boat with fw cooled perkins. Had a marine engine surveyor look at it, he changed one injector and said go and do another 8000 hrs.

They are designed to run and run as long as you keep the oil and water flowing and change out parts as need be.

 

[LittleSister]

I've a 1979 Bukh DV36, direct seawater cooled, with 2,000 odd recorded hours on it. Starts and runs very well (though I did have an injector pump seal failure recently). I would not be put off by one with 4,000 hours, though I would want to see it start and run, and ideally have an engineer check it over.

I have not heard of the water pump having the same problem as the DV10 & 20 series (i.e. if the pump seals fail without early leaking being spotted coming from the weep holes, water gets into the engine), but that does remind me to check the potential for that. (The DV36/48 is a significantly different layout, later design, engine to the DV10/20, though they do share some parts.)

The seawater pump is on the starboard side near the rear of the engine, facing forward, somewhat hidden under the exhaust manifold, and driven by the camshaft etc. gears on the back of the engine. The Bukh freshwater circulation pump (if fitted) is to the rear of that.

The anode is on the starboard hand side of the engine, half-way up, about 1/3 of the way back from the flywheel. There is a big nut in that location (22mm?) which unscrews. The anode, which IIRC is the same as that for the DV10/20 series, screws into the other face of it. Unlike a previous poster, I would be unconcerned by finding a wasted anode That's what they do. Just replace it. There was a discussion on here about Bukh anodes a while ago, and one poster says he's never replaced his, and it has been fine for 30 years.

I'd be interested to know the make/model of the electric circulation pump on your engine when you get to see it. I toy with the idea of converting to indirect cooling, but the cost of the Bukh gear driven circulation pump is unpalatable, and I haven't seen an electric pump with the same capacity.

 

[jtwebb]

The boat spec says the fresh water system is Martec. Many thanks for all the comments, will print some to take when I can visit the boat.

 

[jtwebb]

Many thanks for all the helpful comments from all the above. I will take printout as necessary to take with me when I can get to the boat.